Nauki Techniczne

Archives of Civil Engineering

Zawartość

Archives of Civil Engineering | 2012 | No 4 |

Abstrakt

The paper deals with the application of the eXtended Finite Element Method (XFEM) to simulations of discrete macro-cracks in plain concrete specimens under tension, bending and shear. Fundamental relationships and basic discrete constitutive laws were described. The most important aspects of the numerical implementation were discussed. Advantages and disadvantages of the method were outlined.

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Abstrakt

Nano technology is an emerging field of interest for civil engineering application. Among the nano materials presently used in concrete, nano-silica possess more pozzolanic nature. It has the capability to react with the free lime during the cement hydration and forms additional C-S-H gel giving strength, impermeability and durability to concrete. Present paper investigates the effects of addition of nano silica in normal strength concrete. Three types of nano-silica in the form of nano suspension having different amount of silica content have been investigated. Mix design has been carried out by using particle packing method. X-Ray diffraction (XRD) analysis has been carried out to find the chemical composition of control concrete and nano modified concrete. Further, experimental investigations have been carried out to characterize the mechanical behaviour in compression, tension and flexure. It has been observed that the addition of nano-silica in normal strength concrete increased the compressive strength and decreased the spilt tensile strength and flexural strength. Also, Rapid chloride permeability test (RCPT) has been conducted to know the chloride permeability of control concrete, nano modified concrete, and nano coated concrete. It has been observed that the chloride permeability is less for nano coated concrete.

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Abstrakt

The effect of the initial porosity on the material response under multi-axial stress state for S235JR steel using the Gurson-Tvergaard-Needleman (GTN) material model was examined. Three levels of initial porosity, defined by the void volume fraction f₀, were considered: zero porosity for fully dense material without pores, average and maximum porosity according to the metallurgical requirements for S235JR steel. The effect of the initial porosity on the material response was noticed for tensile elements under multi-axial stress state defined by high stress triaxiality σₘ/σe = 1.345. This effect was especially noticeable at the range of the material failure. In terms of the load-bearing capacity of the elements, the conservative results were obtained when maximum value of f₀ = 0.0024 was used for S235JR steel under multi-axial stress state, and this value is recommended to use in the calculations in order to preserve the highest safety level of the structure. In usual engineering calculations, the average porosity defined by f₀ = 0.001 may be applied for S235JR.

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Abstrakt

One of the contract awarding systems in public sector in Poland is the Design & Build system. In this system, a client concludes a contract agreement with only one company, a contractor, in order to carry out both design and construction of works. While deciding on this form of delivery of a public project, the client is obliged to conduct a single proceeding aiming to select the contractor. In this paper, public works contracts awarded in the D&B system in Poland are analysed, whilst attention was put on the contracting modes and assessment criteria. The results are assessed against the experience of other countries and recommended methods for selection of the Design and Build contractor.

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Abstrakt

In the flexible road pavement design a mechanistic model of a multilayered half-space with linear elastic or viscoelastic layers is usually used for the pavement analysis.

This paper describes a domain selection for the purpose of a FE model creating of the linear elastic layered half-space and boundary conditions on borders of that domain. This FE model should guarantee that the key components of displacements, stresses and strains obtained using ABAQUS program would be in particular identical with those ones obtained by analytical method using VEROAD program.

It to achieve matching results with both methods is relatively easy for stresses and strains. However, for displacements, using FEM to obtain correct results is (understandably) highly problematic due to infinity of half-space. This paper proposes an original method of overcoming these difficulties.

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Abstrakt

The goal of this work is to compare different constitutive models in the nonlinear static characteristic analysis of asphalt concrete core dams. The Duncan E-μmodel, Duncan E-B model and double-yield-surface model are three major constitutive models in the nonlinear static prediction of earth-rockfill dam. In this paper, an earth-rockfill dam with asphalt concrete core-wall in an actual hydraulic engineering is employed to compare the three models. The finite element model of the core-wall dam is proposed. Nonlinear static analysis of the dam is carried out and the static characteristics are obtained to study the differences generated from different constitutive models. Numerical results show that both the stress extremum and the stress distribution of dam body with three different models are coincident one another. In the deformation analysis of dam body and core-wall, the maximum values of sedimentation with the Duncan E-μmodel and the Duncan E-B model, which are greater than the value with double-yield-surface model, are close to the practical test data though the deformation distributions with three models are in good agreement. But, the analysis results of core-wall stress with double-yield-surface model are proper and more reasonable than the other models.

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Abstrakt

The aggregate applied for the wearing course has a significant influence on skid resistance of road surfaces. However, it is difficult to evaluate the behaviour of road surface in use on the basis of the Polished Stone Value (PSV) determined for the aggregate according to the so called ‘British method’. The British method, which is currently used in many countries, does not allow to determine the influence of neither the grain size of the aggregate nor the type of the wearing course on skid resistance of road surface. The present paper suggests a method for evaluation of the British Pendulum Number (BPN) for road surfaces in laboratory conditions. The authors assumed the BPN for polished slabs, made from asphalt mixtures, as the criterion. The index was measured with the British Pendulum Tester. The simulation of the process was conducted on research stand (called slab polisher) built at Bialystok University of Technology (BUT). The results of laboratory tests indicate that surfaces from asphalt concrete (AC) have slightly higher values of BPN in comparison with the values determined for surfaces made from stone mastic asphalt (SMA).

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Henryk Zobel


Deputy Editor-in-Chief
Mariola Książek


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Andrzej M. Brandt
Werner Brilon (Germany)
Jacek Chróścielewski
Luc Courard (Belgium)
Andrzej Garbacz
Andrzej Garstecki
Wojciech Gilewski
Marian Giżejowski
Oleg Kapliński
Piotr Konderla
Aleksander Kozłowski
Marian Kwietniewski
Zbigniew Młynarek
Andrzej S. Nowak (USA)
Anna Siemińska-Lewandowska
Jan Szwabowski
Waldemar Świdziński
Andrew P. Tarko (USA)
Marian Tracz
Edmundas K. Zavadskas (Lithuania)
Jerzy Ziółko

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GUIDELINES FOR AUTHORS

1. Preparation of the paper

General: Author is responsible for the Paper contents including copyrights and text formatting. The manuscript should be written in English. It should be typed using 12 p TNR font with 1.5 line spacing, on single-sided A4 sheets with 2 cm margins. The paper should not exceed 10 pages including tables and figures plus 2 pages of an extended summary (TNR 10 pt. justify align), started from new page at the end of the manuscript. Summary in Polish for Polish natives only, others - summary in English.

The first page and the main text: The first page of the article should contain: (1) the title of the article, (2) the name, academic merits, affiliation and e-mail of each author, (3) the name and the address of the author to whom correspondence, proofs and reprints should be sent, (4) a summary of 50-150 words, (5) a list of key words (not to exceed 8). The main text should be divided into numbered (1, 2, etc.) and titled sections and, if needed, into subsections (1.1, 1.2, ... in Section 1, 2.1, 2.2, ... in Section 2, etc.). The abstract of 50-150 words is required on a separate sheet. Polish natives authors only are requested to enclose Polish translation of the abstract, others - abstract in English.

Tables and figures: Tables and figures should be inserted into the text (black-and-white figures and glossy photographs),numbered consecutively and titled. They should be referred to in the text as Fig. 1, Fig. 2, ..., Table 1, Table 2. A list of figures and tables captions (TNR 11 pt. left align, in Polish - for Polish natives only and in English) should be provided on separate sheet(s) at the end of the manuscript beforean extended summary. Colour figures will be accepted only if the colour is essential for the explanation.

Units and mathematical formulae: SI units and abbreviations are obligatory. Mathematical formulae should be typewritten and centred. The formulae referred to in the text are to be numbered consecutively in each Section, i.e. (1.1), (1.2), ... in Section 1, (2.1), (2.2), ... in Section 2, etc. The numbers should be placed in parentheses ( ) at the left margin. The formulae are to be referred to in the text as Eq. (1.1),, Eq. (1.2), ..., Eq. (2.1), Eq. (2.2), ..., etc. The formulae not referred to in the text should not be numbered.

Bibliography: References are to be listed at the end of the paper in the alphabetical order and consecutively numbered. A reference to a published paper should be referred to in the text by the last name(s) of author(s) and the reference's number in brackets [ ]. Each item should contain full bibliographical data in the format illustrated by the following examples:

[1] M. Abramowitz and I. A. Stegun, Eds. Handbook of Mathematical Functions (Applied Mathematics Series 55). Washington, DC: NBS, 1964, pp. 32-33.

[2] M. Gorkii, “Optimal design”, Dokl. Akad. Nauk SSSR, vol. 12, pp. 111-122, 1961.

(Transl.: in L. Pontryagin, Ed., The Mathematical Theory of Optimal Processes. New York: INTERSCIENCE, 1962, Ch. 2, sec. 3, pp. 127-135).

[3] B. Klaus and P. Horn, Robot Vision. Cambridge, MA: MIT Press, 1986.

[4] E. F. Moore, “Gedanken-experiments on sequential machines”, in Automata Studies

(Ann. of Mathematical Studies, no. 1), C. E. Shannon and J. McCarthy, Eds. Princeton, NJ: Princeton Univ. Press, 1965, pp. 129-153.

[5] R. L. Myer, “Parametric oscillators and nonlinear materials”, in Nonlinear Optics, vol. 4, P. G. Harper and B. S. Wherret, Eds. San Francisco, CA: Academic, 1977, pp. 47-160.

[6] L. Stein, “Random patterns”, in Computers and You, J. S. Brake, Ed. New York: Wiley, 1994, pp. 55-70.

[7] Westinghouse Electric Corporation (Staff of Technology and Science, Aerospace Div.), Integrated Electronic Systems. Englewood Cliffs, NJ: Prentice-Hall, 1970.

[8] G. O. Young, “Synthetic structure of industrial plastics”, in Plastics, vol. 3, Polymers of Hexadromicon, J. Peters, Ed., 2nd ed. New York: McGraw-Hill, 1964, pp. 15-64.

In special cases, other formats related to codes, reports, dissertations, etc. will be accepted.

Layout of the text can be downloaded from ace website: http://ace.il.pw.edu.pl

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Two electronic versions of the manuscript (DOC and PDF file) and License to publish should be submitted and sent directly to the Editor-in-chief by e-mail to: ace@il.pw.edu.pl

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3. Proof read: Proofs will be sent to the corresponding author to correct any typesetting errors. Alterations to the original manuscript at this stage will not be accepted. Corrected proofs page must be mailed to the Editorial Office as soon as possible.

4. Copyright: Submission of a paper to Archives of Civil Engineering implies that the material is an original and unpublished work, not under consideration for publication elsewhere. If permission for publication of any material is required, it should be obtained from appropriate sources by the author. The corresponding author is responsible for the other authors' approval of the paper publication.

5. Reprints: The corresponding author will receive ten reprints and PDF file of the published paper free of charge.

6. Other information: Apart from research papers, other articles such as review papers, brief notes, discussions and reports may be published in the journal. Monographic papers and state-of-the-art papers are accepted after prior approval of the Editor. Reports on important conferences held in Poland may also be published. Editor decides whether the paper fulfil all requirements i.e. formal and scientific. Editor nominates two reviewers, who shall forward reviews of the accepted publication.

The paper will be published in ACE provided that the reviews are positive. If reviewers have some comments authors have to correct the paper. Papers are subject to open discussion. All letters should be addressed to the Editorial Office and will be published together with the authors' response.

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